package com.hxl.servlet;

import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
import java.net.URL;
import java.net.URLDecoder;
import java.net.URLEncoder;
import java.util.Date;

//保存用户上一次访问的时间
public class CookieDemo01 extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //服务器告诉你，你来的时间，把这个时间封装成为一个信件，你下次带来，我就知道你来了

        //解决中文的乱码问题
        req.setCharacterEncoding("utf-8");
        resp.setCharacterEncoding("utf-16");

        PrintWriter out = resp.getWriter();

        //cookie,服务器端从客户端获取
        Cookie[] cookies = req.getCookies();//这里返回数组，说明Cookie可能存在多个

        //判断cookie是否存在
        if(cookies != null){
            //如果存在怎么办？
            out.write("你上一次访问的时间是：");
            for (int i = 0; i < cookies.length; i++) {
                Cookie cookie = cookies[i];
                //获取cookie的名字
                if(cookie.getName().equals("lastLoginTime")){
                    //获取cookie中的值
                    long l = Long.parseLong(cookie.getValue());
                    Date date = new Date(l);
                    out.write(date.toLocaleString());
                }
                if(cookie.getName().equals("name")){
                    //解码
                    out.write(URLDecoder.decode(cookie.getValue(),"UTF-8"));
                }
            }
        }else{
            out.print("这是您第一次访问");
        }
        //服务器给客户端响应一个cookie
        Cookie cookie = new Cookie("lastLoginTime", System.currentTimeMillis()+"");
        //编码
        Cookie cookie1 = new Cookie("name", URLEncoder.encode("哈哈哈","UTF-8"));

        //设置cookie的有效期为一天。设置之后浏览器关闭掉之后cookie还存在
        cookie.setMaxAge(24*60*60);

        resp.addCookie(cookie);

    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req, resp);
    }
}
